Artificial stone.



NITED rnrns PATENT rricn,

JESSE \V. JOHNSON, OF BUFFALO, AND ALBERT S. HENDRIX, OF THORNTON,TEXAS; SAID HENDRIX ASSIGNOR TO SAID JOHNSON.

ARTIFICIAL STON E.

SPECIFICATION forming part of Letters Patent No, 656,696, dated August28, 1900.

I Application tiled October 21,1899. Serial No. 734,361. (No specimens.)

T aZZ whom, it may concern.-

Be it known that we, J ESSE W. JOHNSON, residing at Buffalo, county ofLeon, and AL- BERT S. HENDRIX, residing at Thornton,

county of Limestone, State of Texas, citizens of the United States, haveinvented a new and useful Artificial Stone, of which the following is aspecification.

Our invention relates to the manufacture of artificial stone, andparticularly to a process for manufacturing stone adapted to be used inpositions where it is exposed to the action of the elements, as aregravestones,

monuments, and the like; and a special object of our invention is toprovide a stone adapted for the indicated use which will not becomesuperficially cracked by reason of exposure and which may be readilyengraved, impressed, or otherwise marked to form letters, characters,emblems, &c.

Further objects and advantages of the in vention will appear in thefollowing description and will be particularly pointed out in theappended claims.

In practice we form the body portion of the stone of a mixture, in aplastic state, of cement (Portland) and flint-sand, preferably coarse,said cement and sand being combined in the proportions of two of theformer to three of the latter by weight, sufficient water being added toreduce the mixture to the desired consistency. In order that a uniformfilling of the mold may be accomplished, we have found it desirable toreduce the mixture of Portland cement and coarse flint-sand, forming thebody portion of the stone, to the consistency of a thin mortar; but inintroducing the same into the mold we only partially fill the latter,leaving a space at the top thereof or at that side of the stone which isto receive the lettering or marking depressed approximately one-halfinch below the upper edge of the mold. This space, which is left in themold for introducing the mixture form- 5 ing the body portion of thestone, we subsequently fill with a mixture of Portland cement (threeparts) and fine flint-sand (one part) reduced by water to a thin mortar,and after thus completing the filling of the mold 50 by forming a layerupon the body portion of a thickness of approximately one-half inch westrike or smooth the exterior surface of said layer and allow thematerial to set for two or three hours. When the surface layer,consisting of cement and fine flint-sand, has set sufficiently, weengrave the characters such as letters, emblems, &c.therein and thenallow the material to harden sufficiently to adapt it to be remoyed fromthe mold without breaking or distorting it, an interval of fromtwenty-four to thirty-six hours being required for this purpose. Afterremoval from the mold the previously-covered surfaces, or all of thesurfaces with the exception of that which was exposed while in the moldand which, as above described, was treated with a layer of cement andfine flint-sand to receive the characters, are coated with a mixture ofPortland cement (three parts) and airslaked lime, (one part,) saidmixture being reduced by water to a consistency adapting it to beapplied with a brush, and thus spread uniformly over those surfaceswhich are not formed by the above-described mixture of cement and finefiint-sand. After applying this surfacing-coat of cement and lime thestone is allowed to dry slowly, the same preferably being exposed to amoderate heat, such as may be obtained in the shade, it beingundesirable to expose the block to the direct rays of the sun. Alsoduring this drying step of the process we moisten the stone at intervalswith water, applied superficially-as often, for instance, as two orthree times a day for a period of a week-after which it is allowed tothoroughly dry and harden. The final step in the process consists incoating the entire surface of the stone with a mixture of flake zinc,ground in oil, mixed with an equal quantity of boiled linseed-oil, saidmixture being applied with a brush while the stone is in a heatedcondition, the same preferably being heated to a temperature of 110to'115 Fahrenheit.

From the above description it will be seen that the body portion of theartificial stone formed in accordance with our process consists ofPortland cement and sand, having a surface coating, except upon the sideor sides to receive the impression of characters, of cement and lime,air-slaked lime being pre-- ferred, and such coating being applied in aliquid state by means of a brush, whereby a I harden; subsequentlyapplying to the unoruniforin layer is formed. Furthermore, it will beseen that when letters or other characters are to be formed in thesurface of the artificial stone the block is provided with a layerformed of Portland cement and fine flint-sand, whereby the formation ofthe characters may be accomplished with facility and leave smooth hardsurfaces. Finally, the entire surface of the block is treated to acoating of flaked zinc and boiled linseed -oil, whereby the intersticesor pores are filled and the material is otherwise rendered durable, thesurface of a block of artificial stone thus coated not being cracked byexposure to the elements.

Having described our invention, what we claim is 1. The process ofmanufacturing artificial stone having an ornamental surface, whichconsists in molding part of a body portion of Portland cement and coarseflint-sand in a plastic condition; completing the molding of the bodyportion of Portland cement and fine flint-sand in a plastic condition;then striking off the exposed surface of the last-molded portion, uponwhich the ornamentation is to be produced, and allowing the material toset; subsequently engraving the characters forming the ornamentation inthesurface of the last-molded portion and allowing the stone to namentedsurfaces of the stonea liquid coating of Portland cement and air-slakedlime and finally applying to the entire surface of the stone, a mixturecomprising flake zinc ground in oil, and linseed-oil.

2. The process of manufacturing artificial stone, which consists inmolding part of a body portion of Portland cement and flintsand;completing the moldingof the body portion with a surface layer ofPortland cement and flint-sand wherein the proportion of cement isgreater and of sand is less than in the first-named mixture; thensmoothing the surface of the last-named mixture and allowing the same toset; then engraving the ornamentation in the surface of the lastmoldedportion and subsequently, after allowing the stone to set, applying aliquid coating of cement and air-slaked lime to the unornamentedportions, and finally applying a coating to all surfaces of oil and apigment.

In testimony that we claim the foregoing as our own we have heretoaffixed our signatures in the presence of two witnesses.

JESSE W. JOHNSON. ALBERT S. HENDRIX.

Witnesses:

WM. GILFORD, A. L. BRADLEY.

